Stoker construction



March l5, 1932. c. F. MILLER STOKER CONSTRUCTION Filed April 4, 1931 2Sheets-Sheet ATTORNEY |NvENToR Cnr-nanas E MxLLEra.

WITNESSES 'March l5, 1932. F M|| ER 1,849,105

STOKER CONSTRUCTION l S! ll.

WITNESSES: INVENTOR jm a CHHRLES F'. MxLLEa. Y BY ail/M- ATTORNEY 30spaces or channels is facilitated.

Patented Mar. l5, l1932' -UNrrED-STA ENTI OFFICE;

. CHARLES F. MILLE-R, OF MGORES, PENNSYLVANIA,- ASSIGNOR TyWES'lINSEE-I0USE.IEG-l 1 `'raro aannnnrnc'rnnms ooMrAnY,

A -coRPQRAToN or TENNSYLVANIA sToKER 4coiss'rmior10N ,Application fue@April r,

My invention relates to combustion kap'- paratus and more particularlyto 'progressive vfeed stokers ofthe multiple retort underfeed type'. K y

l' he invention has 'for'an object to provide a structure of this typewhich is ofimproved construction and arrangement of parts.

A further kObjectis vto provide a structure of this character. which isextremely strong g1g and durable, is very Vlight and is .cheap tomanufacture. .y

A further object of'my invention is to provideafcomposite beam structureconsisting of an upper cast part and a lower steel tenf sion rod. Thisstructure Vpermits the upper cast lor compression part to be made ofminimum depth and thickness, whereby the ready ingress of lair into thetuyere' channels or spaces is interfered with to aminimum eX- v,2,0tent. y Furthermore, as the tension rods are spaced romthe castcompression portions of the composite beam structures, kair may iiow.freely underneath the cast portions of the beamsand enter into the tuyre`spaces or y,'1-#25 channels. Therefore, a further object of myinvention is to'provide a composite beam structure ofl this character sothat the ydis-v tribution .of air `to the tuyre spaces or chan-- nelsand the ready ingress of air into such 'lhese and other objects areeii'ected bymy invention as will be apparent from the ollowingdescription and claims, taken in con` nection with the accompanyingdrawings, and V`formingA a `part of this. application, Vin which: n

Fig. 1 isa `longitudinal` sectional view through a retort oia Stokerconstructed in accordance with the present vinvention;V jv i Eig- 2 'isa planpview of thestoker shown. in Eig. 1, illustratingthe arrangementofthe retorts and tuyere rows, certain parts Vbeing omitted fromportions of the stoker to illus-r trate more clearly the detailstructure., and,

' is avfragmentary transversesection taken on the line III-,III of. Fig.l. y y According -tothepreferred embodiment of myrinvention'which isshown on 'the accoms psrlying drawings, Irrovds iii @furnace a V5.0frgnt: and' vrear supporting "structure anda 19311,.. Yserif-.i No.bams.'

Stoker of the vtype comprising parallel 'alterik nately-arranged retortsand rows of tuyres, which stoker extends between and iscarried by thesupporting structures. "The Stoker comprises a plurality of pairs' oflongitudinally-extending beams carriedby 4the supf porting structures,.the beams of' .each pair being spaced apart a distance equal 'tothewidth of the retorts, a tension truss rod eX- tending"longitudinallybeneath each beam l and .secured at its ends to the opposite endportions Vor' its respective beam, a strut .for spacing the rod from thebeam,'and'tuyeres and retort-forming elements carried by the.

beams and including upright plates secured *totheU beams to form retortyside walls. i

Referring now in detailtothe construction illustrated, the referencenumeral lOindicates a Stoker of the downwardly inclined multiple retorttype. Thestoler comprisesfparallel, alternately-arranged retorts 1-1Vand frows of overlapping tuyeres 12. 'llhe upper or-frontportion'othe.stoler is .carried byy ya'front supporting construction 13including'atrans- `verse girder l and -castings `15-bolte`d 'to theupper face of the girder, and the 'liower'or 'rear portionof vtl'ieStoker is slidablycarried by" a rear Supporting construction 16Qomprising .a girde'r 17 'and castings 19'slidably 'supported bythegirder 17.

The stoker is ofiia-broatedj Constructioniand inCludss s supportingframework Comprising s' plurality Qi pairs 0i spared. .supporting beams18 carried at their upper' and lower ends by the supportingconstructions1.3 and 16, respectively.l Thebeamsf 18er each pair are spaced apart adistanoeequalto .the` Width of theretorts,`and areheld in this relation'byihs Castings 1,5. and. lathe. .extremities .f

the beams bring' securely belted its .portiers .of thefcastings.v Thepairs of beams. .are

spaced'aparta distance equaltothe width of the tuyere rows, lthis'beingaccomplished Y constructing-the. castings in widths equalfft'o4the distancsfbstwssri. the: .Csrltsr lines' 'Qi 'ad-- .isssntituyre rowsand. iir'siispesirlgths 'esst' ings in 'abuttingsirbyfside' relation'jupon 'theirrespetivegirders i, Y.

The' beams. 18 may be constructed ,of any suitablel material, forexample, eastiron, In

CJ' supporting elements.

order that the beams be sumciently strong to support the remaining partsof the stoker as well as the fuel bed and in order that the beams may beas light as possible, I provide 5 a tension truss red 20 which isdisposed beneath and longitudinally of each beam and is secured at itsends to brackets 2l and 22 formed on the opposite ends of each beam. `Acompression strut 23 depends from the centrai portion of each beam andserves to space the truss rod from the beam. Adjustable tension means isprovided for tensioning each rod 20. For example, the nuts 21a and 22acarried by the threaded'ends of the-rod may l5 be utilized for thispurpose; however, each rod 2O is preferably divided intermediate itsends, and a turnbuckle provided for tightening the rod and forfacilitating its assembly and removal. The beams 18 and 19 are separatedfrom the heat of the fuel bed by more refractory cast metal parts of thestoker. These latter parts are the tuyeres and the retort-formingelements. The retort-forming elements com- 25 prise upright cast metalplates 25 bolted to the sides of the beams to form the retort sidewalls, and bottom forming members including guide or bottom plates 26disposed between the side walls of each retort and sup- 30 ported bybrackets 27 extending from the plates 25, and secondary rams 28 slidablysupported by theplates 26. The overlapping tuyres l2 span the distancebetween and are supported by the adjacent side walls of adj acentretorts.

The'operation of this type of stoker Vis well known. Green coal is fedinto the ends of the retorts ll from a hopper 30 by means of primaryrams 37 reciprocating within ram 4.10 boxes 32. The coal is advancedalong the retort and forced upwardly and laterally onto the tuyere rowsby the secondary rams 28. The resulting ash is discharged from therear-'or lower end of the stoker by any suitable means, not shown.

By reason of the fact that the stoker is constructed in the mannerdescribed, the beams which are' an inherent part of the stoker'structure may be relatively light, the maj or portion of the requiredstrength of the beams being supplied by the tension truss rods. Thestoker may be eXtended to great lengths without necessitating the use ofcumbersome and bulky stoker parts or the use of intermediate The beamsperform the load-carrying function of the retorts and are protected fromthe heat of the fuel bed by` the tuyre and retort-forming elements.Furthermore, since each of the beams is rein- I forced by its tensionrod, each beam may be made of minimum depth and thickness, therebyminimizing interference on the part of the beams with free ingress ofair into-the tuyere channels or spaces. Also, as it is pos- -35 sible tominimize the depth of the beams due to the presence of the tension rodsand as the rods are spaced from their beams, the composite beamstructures permit of the free flow of air between the rods and the beamsproper and the ready entrance of air into the tuyere spaces or channels.The non-interference with the flow or `distribution of air in anunderfeed stoker is a matter of importance' not only in supportingcombustion more uniformly but in cooling the tuyres and preventingeddying which usually results in rapid burning out of tuyeres subjectedto eddying air or gas flow 'eifects Hence, the strains setup in the-tuyere and retort forming elements due to heat are not transmitted tothe beams. Furthermore, if any of the tuyre or retort-forming elementsshouldburn out, the affected part or parts may be readily replacedwithout disturbing thev other structure.

Heretofore, cast iron supporting beams have been used to carry underfeedstoker retorts; however, such beams have usually been so constructed asto constitute the retort side walls. lt has not been feasible to carrythis construction to extreme lengths and furthermore it is objectionableon account of the beam element burning out. In accordance with thepresent invention, the beam elements do not constitute retort side wallsbut support and position retort side walls formed separately therefrom,and each beam is of a composite character comprising an uppercompression portion made of cast iron, which is very strong incompression, and a lower tension rod made of steel, whereby the beam maybe made relatively light and is suitable for supporting very longretorts without the use of intermediate supports. This type of beam ,Y

is particularly advantageous for supporting fuel contacting parts, asthe cast iron compression portion thereof is inherently capable ofwithstanding high tempera-tures even though subjected to highcompression stress, this being the portion of the beam which is adjacentto the fuel bed. Also, as pointed out, due to the' open girderformationv of the beam, interference with distribution and supplying ofair to the tuyere spaces or channels is interfered with to a minimumextent.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but issusceptible ofvarious changesand modifications, without departing from the spiritthereof, and I desire, therefore, that only such limita.- tions shall beplaced thereupon as are imposed by the prior art or as are specificallyStoker extending between and'carried by the n supporting structures andcomprisinga plu'- rality of pairs of longitudinally-extending parallelbeam members carried by the supporting structures, the beams of eachpair being spaced apart a distance equal to the width of a retort, atension truss rod extending longitudinally beneath each beam and securedat its ends to the opposite end portions of its respective beam, acompression strut for spacing the intermediate portion of each rod Jfrom,ico

its beam, and tuyres and retort-forming elements carried by the beamsand including upright plates secured to the beams to form retort sidewalls.

2. In a furnace, the combination'of spaced supportingstructures,parallel alternately-'arranged retorts and rows of tuyresproviding an inclined multiple retort underfeed stoker extending betweenand carried bythe sup`` porting structures and comprising a plurali-v tyof pairs of longitudinally-extending parale lel beam members carried'bythe supportincluding upright plates secured to the beams to formretort side walls. Y

In testimony whereof, I have hereunto subscribed my nameI this 2nd dayof April, 1931. u CHARLES F. MILLER.

